According to Wikipedia:
Homeric Greek does not have a historical present tense, but rather uses injunctives. Injunctives are replaced by the historical present in the post-Homeric writings of Thucydides and Herodotus.
But also according to Wikipedia:
Ancient Greek has words that are formally similar to the Sanskrit injunctive mood, consisting of aorist and imperfect forms lacking the augment. However, in this case there is no difference in meaning between these forms and the normal augmented forms.
I'm a bit confused: the first quote seems to be saying that injunctives are something special, separate from the aorist or imperfect, while the latter says the opposite.
So: are these "injunctives" really a special form in Homeric/Epic Greek, separate from the aorist and imperfect? And is there any difference in meaning between an "injunctive" and an aorist form, e.g. that might make the former equivalent to a historic present and the latter not?